1. Field of the Invention
The present invention relates to growing and living facilities for hogs, and more particularly to farrowing operations and equipment including the use of large pen gestation facilities for sows, and more particularly still to a system for improving the welfare and performance of gestating sows in a large pen environment and for improving the grower's accessibility to the sows for managing purposes.
2. Preliminary Discussion
A critical aspect of pork or swine production is the continual provision and supply of new piglets, or farrows, for growing. Management of pregnant or gestating sows is thus critical, and keeping the sows comfortable and healthy will improve the likelihood that healthy farrows will be born and also increase the overall successful gestation rate. Gestation facilities are used to house sows that are both not yet pregnant or are pregnant but have not come to term. The primary goal of a gestation facility is to provide sows with a living environment that is comfortable and accessible. Accessibility applies to both the sow and the grower. The sows require access to food and water, while the grower requires access to the individual sows.
In early farming, many or most farmers would maintain one or two hogs or pigs in the farm pigpen where they grew to the desired size and were then slaughtered for personal or home consumption, or if more pigs were maintained than required for personal or family consumption, some would be sold for slaughter and for consumption by other farmers, or shipped off for ultimate consumption by city dwellers. Later, some farmers began to specialize in hog growing or relatively large-scale hog production. In these operations there tended to be specialization between fattening hogs for market or raising breeding sows for sale to the fattening operators or operations known generally as “finishing” the hogs for market. Since some of the female pigs, or sows, were not slaughtered until their breeding days were over, special care was taken in their raising and care and in more recent or relatively recent times the sows were maintained separately in fields provided with individual houses or covered pens for shelter of both the sows, and when their piglets were born, also the newborn piglets and young pigs, both male and female, both of which would then be sent to so-called finishing operations for fattening or raising to suitable size for market. Special female pigs, or sows, and a very few special male pigs or boars, would be reserved for breeding as needed.
As time passed, it was discovered that the mixing of different sows as well as their young pigs in the fields not only took too much acreage, as land became more expensive and also tended to spread disease between the sows and between their young after birth and gradually farrowing operations, which includes generally the breeding or insemination of sows, gestating the sows for approximately 100 to 110 days and then birthing of the sows to produce piglets, began to be conducted under cover with each sow kept in her own relatively small pen close to, but physically isolated from other sows in the same farrowing operation. This also had the advantage of having the location of any given sow at any given moment predetermined so that by keeping track of the breeding of each sow, usually by artificial insemination, it would be known when such sow would be ready for birthing and, if special birthing rooms or pens were being used, the particular sow could be moved to such birthing room or pen and give birth there where special attention to the newborn piglets could be given. Alternatively, the sow could simply be left in her pen for birthing, providing special arrangements to prevent harm to the piglets after birth by being crushed to death beneath their outsized mothers. Since the sows were continuously confined in their own pen, special attention for monitoring their pregnancy, the giving of medicine, and tests to make sure they were actually gestating and hadn't accidentally aborted or failed to conceive could be easily given to each sow in turn or according to a predetermined schedule. A number of inventions with respect to special stalls or pens and other equipment for this type of operation were made and patented during this period and continue to be developed and patented.
Relatively recently, certain disadvantages with the pen system of farrowing have come to the fore including lack of comfort of the sows, the amount of labor involved in keeping track of the animals and conveniently accessing such sows in their long rows of individual pens, agitation of the animals simply from the frustration of the animals at being closely penned, leading to wild and unpredictable behavior, and the like. Being continuously confined, furthermore, results in a build-up of tension in the sows with consequent decrease in their health and the health and size of their litters, probably because of unleashed long-term tensions, which are evidenced by excitability and restlessness. Agitation of all the sows during feeding, each animal wanting to be fed first, and general agitation whenever an attendant entered the building plus general confinement stress was perceived gradually to be, in fact, detrimental to the health of the sows as well as the young being gestated and in addition, animal rights activists also began to take up the case of the animals and regulations began to be promulgated requiring minimum amounts of space for each animal.
Pigs or hogs are generally social animals which in the wild tend to travel in groups from one feeding area to another maintaining relatively close contact with other animals in the same groups both for support and for better location of productive feeding areas. Isolating hogs in individual pens deprives them of close contact with other animals and makes them generally nervous and unpredictable and as noted above, is believed to be detrimental to the general health and birth weight of young newborn piglets.
As a result of the foregoing disadvantages of individual penning of sows during gestation so-called “open pen” gestating facilities or arrangements have been adopted by some growers, in which, after breeding or artificial insemination of the sows, such sows are, after preliminary artificial insemination, which takes place usually in individual pens, where such sows may then be kept for a period such as twenty-eight days to make sure that the individual embryos have become securely attached to the wall of the sow's womb, released into an open style gestating pen similar to open pen pig finishing operations, although a sow may be released immediately, or after a few days, if the farrowing operation is short of impregnation pens. Since it takes a finite time after actual impregnation for an embryo to become securely attached to a sow's womb, poking of such sow's belly by other sows or pigs may sometimes result in an aborted fetus. This, however, become less likely as the end of a 28 day implantation period approaches. The sows in this type of operation are released into a large pen, allowing the animals to have essentially full social contact with other similar animals. While this has been provided in some cases, and it is believed, results in more healthy young piglets, it has had two major drawbacks, namely fighting and difficult, or even complete, lack of access to the animals by the growers.
Farrowing operations are inherently somewhat individualized operations in which each sow may require individualized attention due to special needs such as special food for some sows, medical care for others, individualized removal for various reasons including particularly the time approaching for birth, possible injury from other animals and the like. It is particularly desirable to remove the animals at least once and possibly several times to test for continued pregnancy, else a non-pregnant sow may spend many days in a sow gestation operation eating special food, and ultimately be found when it is time for birthing not to even be pregnant. (More recently ultrasonic pen testing has been available in large operations.) These animals may be about four to five hundred pounds in weight and are extremely difficult to cull or sort out of a group of similar animals, since the individual animals have “minds of their own”, plus as might be suspected, are inherently suspicious of being herded, so to speak, in a contrary direction from their pen mates or other sows in a pen. While the individual animals are, therefore, not inherently dangerous under most circumstances, it will frequently take several grown men to sort or cull them out of a multi-animal or so-called open pen, one man to guard and open and close the gate to keep other animals from escaping and two to urge the sow toward the gate while discouraging movement of her pen mates in the same direction. Such culling or separation is obviously time consuming and expensive in operation time.
The other major problem in open pen environments is fighting at feeding time when sows tend to “hog” all the food, a characteristic of the animals as shown by the growth of the universality of the slang term. A further problem in open pen environments is non-feeding fights which usually results from certain sows taking a dislike to other sows for whatever reason. Again, because hogs are social animals, individual fighting is not continuous, but rather sporadic as animals take specific dislikes to each other or some particular pen mate. Where there are more than a few animals in one pen, there may be one sow, which, for some reason not usually evident to the managers of the pen is unpopular with other certain sows or which some other sows just do not like and if some way to allow actual separation of these animals from the others which do not like them is not available, the objected to individual sows may be actually killed. Frequently these individualized battles can be resolved simply by having a large enough pen to allow the picked upon sow to get away by herself or away from her attackers or potential attackers, but otherwise such sow must be removed from the pen on a high priority basis and to do this she must be culled out or removed to an individual pen usually on an expedited basis.
3. Description of Related Art
The following patents of which the present inventors are aware provide among other things a general history of the development of farrowing operations from earlier portions of this century to the present.
U.S. Pat. No. 1,309,071 issued Jul. 8, 1919 to F. G. Johnson provides a heated farrowing house having hollow air insulated walls with several pens disposed within and with a central section in each pen partitioned off by a suspended circular barrier in which small pigs are kept, the size in general making it most convenient for a brood sow to lie with her nipples extended centrally where the small piglets are maintained. While this arrangement provides more room for individual sows than the usual pens and is intended to keep the piglets safe from being lain upon, there do not appear to be multiple sows in one pen, so separate management of gestating sows is not necessary.
U.S. Pat. No. 1,590,982 issued Jun. 39, 1926 to E. B. Morris discloses a heated farrowing house having a half dozen separate pens within a hexagonal structure.
U.S. Pat. No. 1,765,925 issued Jun. 24, 1930 to W. Lodize discloses an advanced design for the usual multiple pen farrowing houses having an improved arrangement for working, but still comprising essentially a separate pen for each sow.
U.S. Pat. No. 1,788,244 issued Jan. 6, 1931 to J. E. Larson discloses an animal house for small pigs having a common central feeding bin from which all the pigs may eat with coil spring means to especially keep larger animal confined in limited individual areas of the building.
U.S. Pat. No. 1,858,699 issued May 17, 1932 to W. D. Bayley for a farrowing house specifically including a heated “housing” space or enclosure to which small piglets may retire to, but which is separated from enclosures for sows. Individual hog pens are adapted to be moved against the separate heated housing space enclosure in cold weather. While allowing piglets access to the central heated housing space, the sows are still apparently restricted to the separate farrowing houses, however, but receive heat transferred from the heated central building.
U.S. Pat. No. 3,042,000 issued Jul. 3, 1962 to P. H. McMurray et al. discloses a farrowing equipment arrangement including a separate pen for each sow in which farrowing takes place and the piglets are weaned. The floor includes a series of close together strips or boards standing on edge which allows pig waste to drop down and be conveyed away by conveyor means below. A central conveyor screw or conveyor is provided between individual pens for the sows to bring feed to the sows. In addition, separate smaller pen enclosures are provided at the sides of the larger pen enclosures for the accommodation of piglets in areas near the sows, but in which the sows will not fit, thus tending to protect the piglets from accidental crushing and provide them with more room for movement.
U.S. Pat. No. 3,137,270 issued Jun. 16, 1964 to P. D. Rigterwik et al. discloses a sanitary slotted floor for hog facilities including drainage and cooling arrangements. Such floor is now apparently commonly used in all major hog buildings.
U.S. Pat. No. 3,148,663 issued Sep. 15, 1964 to W. J. Conover discloses a circular farrowing building incorporating essentially truncated triangle-shaped adjoining individual stalls or sow pens. The arrangement enables a central feeding system to be conveniently used.
U.S. Pat. No. 3,191,578 issued Jun. 29, 1965 to G. H. Magruder discloses an irregular combined farrowing and finishing unit for hogs. The sows are still maintained separate from each other so that their limited location allows them to be easily accessed.
U.S. Pat. No. 3,216,396 issued Nov. 9, 1965 to W. H. Scamman discloses a pig farrowing house in which the sows are limited to movement within a restricted space by a barrier-type gate positioned a distance away from the floor to allow pigs through, but to restrict movement of the sows. Opposite the barrier is a broader section large enough for piglets and small pigs, but not large enough for a full-grown sow, and therefore, not subject to occupation by a sow.
U.S. Pat. No. 3,416,496 issued Dec. 17, 1968 to D. L. Peterson discloses a restricted space farrowing house, which prevents major movement by sows in order to protect small pigs from injury.
U.S. Pat. No. 3,584,603 issued Jun. 15, 1971 to D. C. Rutherford discloses a farrowing house arrangement in which sows are restricted to individual stalls or pens, but providing a specially constructed floor which is claimed to remain dry and sanitary more easily. It is disclosed by Rutherford that until fairly recently sows were customarily bred in a small farrowing house in an open field. In such arrangement the sows were free to roam around the open field and mingle with other sows and their respective young piglets. However, more recently pork producers have found that if the sows and piglets are confined to a building which is properly sanitized there is less disease and if such buildings are properly engineered, fewer piglets are accidentally killed by the sows.
U.S. Pat. No. 3,225,737 issued Dec. 28, 1965 to H. Bicket discloses a pig rearing house or piggeric having closely confining pens arranged to maintain as much as possible the temperature near sow body heat temperatures and to require the minimum necessary movement together with good oxygen circulation plus automatic sanitation.
U.S. Pat. No. 3,726,254 issued Apr. 10, 1973 to W. J. Conover discloses a multistory farrowing structure arranged to recover food not eaten by younger animals on higher levels and feed it to pregnant sows on lower floors with the interesting result that the pregnant sows are automatically inoculated with certain disease organisms affecting young pigs and, it is claimed, build up antibodies against such disease or diseases which antibodies are transformed to their subsequently born young.
U.S. Pat. No. 3,749,060 issued Jul. 31, 1973 to J. Wagner discloses a circular pen arrangement for broad sows and piglets in which either the individualized pens rotate within food supplies and waste disposed facilities on a daily controlled scheduled or alternatively the food and waste facility equipment moves past the individual stalls.
U.S. Pat. No. 3,994,548 issued Nov. 30, 1976 to R. N. Lindvall et al. discloses an early sow monitoring system to keep track of individual sows by the use of individualized cards coded with ear numbers for sows and placed in a rotatable carousel which advances one compartment a day to keep track of what sow must be handled on what day. It is indicated that the health of sows is increased if they are kept in a farrowing crate during the farrowing period and the mechanical apparatus of the invention facilitates this type of record keeping.
U.S. Pat. No. 4,027,628 issued Jun. 7, 1977 to R. M. Butler et al. discloses a mechanically operable feeding network particularly to control the feeding of sows during gestation. The apparatus is particularly useful for regulating the access of sows to feed on a regular basis.
U.S. Pat. No. 4,227,485 issued Oct. 14, 1980 to D. I. Poore discloses an individualized farrowing house.
U.S. Pat. No. 4,269,146 issued May 26, 1981 to C. L. Linderman provides a further specialized or individualized hog farrowing house.
U.S. Pat. No. 4,359,967 issued Nov. 23, 1982 to S. L. Cornelson discloses a cast concrete farrowing house made in an “A” frame form.
U.S. Pat. No. 4,471,719 issued Sep. 18, 1984 to C. Thompson discloses a sow farrowing stall constructed and having a shape preventing a sow from lying on her piglets.
U.S. Pat. No. 5,099,793 issued Mar. 31, 1992 provides yet another individualized farrowing shed.
U.S. Pat. No. 6,382,135 issued May 7, 2002 to E. V. Groothust et al discloses yet another arrangement for individual pigpens with restraining rails to keep birthing sows from lying on their piglets.
In addition to the above noted sampling of some of the earlier prior art, the present inventors are aware of the following prior art references which have taken the food animal husbandry industry and the farrowing industry into the computer age and may in some cases seem to have some bearing upon the present applicants' invention.
U.S. Pat. No. 3,788,276 issued Jan. 29, 1974 to R. I. Propst et al., entitled “Animal Marking Apparatus and Method,” provides a method and means for tagging livestock animals and keeping track of such animals by means of tag reading means.
U.S. Pat. No. 4,288,856 issued Sep. 8, 1981 to G. S. Linsith, entitled “Livestock Feedlot Management Method and Apparatus,” discloses an early use of a programmable microprocessor and progressive weighing of animals passing through the scales to keep track of and sort animals having different weight gains and losses.
U.S. Pat. No. 4,517,923 issued May 21, 1985 to T. Palmer, entitled “Animal Feeding System,” discloses another electronic animal monitoring system, which not only monitors animals electronically but adjusts the feed of the animals accordingly. It is disclosed that various other information in addition to weight may be included in the computer monitoring system including breeding information such as coming into heat dates, times bred dates, calving dates, estimated due dates and the like information useful in the management of a dairy herd may be collected. The feed provided by individualized feed stations may be controlled.
U.S. Pat. No. 4,617,876 issued Oct. 21, 1986 to N. J. Hayes, entitled “Animal Identification and Control System,” discloses using electronic identification tags and particularly ear tags to admit livestock to special feeding stalls where specialized feeding for specific livestock may be applied and other information obtained by a scale in the feed stall. Various other information may be kept track of including the last time a given animal ate. Different visual numbers may be used for the identification of the animals from electronically used unique code number for each animal.
U.S. Pat. No. 4,712,511 issued Dec. 15, 1987 to D. D. Zanzow et al., discloses a fairly sophisticated computer management control system for livestock including specific food mixes for specific animals based on information obtained concerning the specifically identified animal.
U.S. Pat. No. 5,069,165 issued Dec. 3, 1991 to V. Rousseau, entitled “Livestock Feeder System,” uses auger systems for feeding animals based upon individual computer controlled data identifying an animal electronically.
U.S. Pat. No. 5,241,924 issued Sep. 7, 1993 to S. Lundin provides an electronic system to manage cows in individual feed stations.
U.S. Pat. No. 5,309,864 issued May 10, 1994 to J. Harmsen, entitled “Method and Apparatus for Feeding Animals,” discloses an animal feeding arrangement for feeding animals and particularly sows in individual farrowing feed pens. An electronic identification system is used to identify individual sows when they enter individual feed pens. The animals can be fed individually based upon the information provided by their transponder. Harmsen explains the advantages of open pen housing of pigs and indicates fighting can be alleviated by feeding all the animals at the same time.
U.S. Pat. No. 6,000,361 issued Oct. 14, 1999 to W. C. Pratt is a classic electronic identification patent making use of electronic identification tags for livestock to sort such livestock according to weight and other factors.
U.S. Pat. No. 6,539,896 issued Apr. 1, 2003 to J. K. Larson discloses a carousel type feeding arrangement making use of electronic transponders with unique codes for different animals to control specific feeding schedules. The system is particularly applicable to use for so-called cattle. It is disclosed that it may be applied, however, to sows. It is specifically disclosed that the transponder can be used for separation of a sow for insemination or farrowing or the like. A carousel feeder is used because it is said to conserve space.
U.S. Pat. No. 5,579,719 issued Dec. 3, 1996 to S. J. H of et al., entitled “Method and Means for Quasi Ad-Libitum Feeding for Gestation of Sows in Loose Housing,” discloses a sow feeding system providing an apparent free range or open pen arrangement having a feed pen within it capable of feeding a series of sows at one time with electronic control of the amount each sow is provided.
U.S. Pat. No. 6,805,078 issued Oct. 19, 2004 to R. C. Zimmerman, entitled “Livestock Weighing and Sorting Apparatus,” discloses a sorter and gate arrangement for sorting out by weight a series of pigs while keeping track of them by computer means. It is disclosed that after hogs have passed through the apparatus during a given time period they become very calm in traversing the apparatus.
U.S. Pat. No. 6,899,044 issued May 31, 2005 to R. M. Thegault et al., entitled “Swinging Gate Assembly Electronic Livestock Feeding Station and Automatic Sorter System,” discloses a particular gate construction for use with electronic sorting systems for sows.
U.S. Pat. No. 7,073,459 issued Jul. 11, 2006 to J. K. Larson is a continuation-in-part of Larson's earlier patent to a carousel-type electronic feeding system applicable to sows.
So-called slow feed systems, such as “Trickle Feeding” systems sold by Automated Production Systems of Assumption, Ill. are feeding systems used for various animals and birds which conveys feed pellets or the like usually by auger means to a reservoir which holds whatever amount is conveyed to it, and then releases such feed pellets through an opening which allows only enough food to drop from the reservoir onto a feeding surface as one animal can eat at a time, or in some cases at a rate equal to the slowest eater in the group.
While the earlier prior art systems and facilities for housing sows during farrowing discussed above are useful for their own particular indicated purposes, and the earlier ones mainly are for historical purposes in tracking the development of the art of farrowing, none gives swine producers sow-level access to individual sows in a large pen sow gestation facility. The present inventors' system for automating the flow of sows in gestation facilities to improve individualized access to sows, however, fully meets the needs of both the sow and the grower in a large-pen design by creating a well-defined flow in the facility and providing equipment to perform sow-level tasks and alter flow as needed. Individual sows are easily kept track of and are able to be individually managed for a variety of purposes while still maintaining a communal living system. When combined with a so-called trickle feeding system moreover a much more peaceful and tractable large pen gestation facility and operation is obtained which is both easier, more healthful, and efficient to operate than previous farrowing arrangements.